However, Google has remained steadfast in its belief that these concerns are unfounded. Chairman Eric Schmidt has even gone so far as to reject suggestions that the company will need to alter the way it handles search results in the EU.

Part of this reluctance to negotiate may stem from the letter's vague explanations. It doesn't exactly pinpoint how Google is breaking the law and which laws it is breaking. Instead, the Commission lays out these four Google antitrust concerns:

Google displays links to its own specialized search engines, such as for restaurants or news. These look different, which the Commission claims "may result in preferential treatment" of its own services to the detriment of competitors.

Google "may" be copying material from competitors and integrating it into its own specialized search services. The commission is "worried" this will discourage creation of original content.

Google's search advertisement contracts require partners to get all or most of their search advertisements from Google.

Google's AdWords platform is not portable to other, competing platforms.

Even though regulators have conducted a "large-scale market investigation," there is a lot of "may" in the letter. Something a little more concrete may be needed before Google is willing to head to the negotiating table.

That table may also soon be needed in the U.S. The FTC and EU antitrust officials have been working closely on this investigation, according to The New York Times. They've been speaking at least twice a week. This suggests that they, too, may also be ready to hand Google an ultimatum.

It's unclear whether Google will also reject such an offer, but it might be wise not to. Regulators in both jurisdictions are also gunning for Android, and a little cooperation might head them off.